A suicide car bomber hit a convoy of security contractors in the Afghan capital today, killing two foreigners, including an American, and wounding three others, police officers said.

The blast in eastern Kabul killed an American and a Nepalese contractor, said Gen. Ali Shah Paktiawal, head of criminal investigations for Kabul police. Three other American contractors were wounded, he said.

The bomber also wounded two Afghan civilians in the attack, said Najibullah Samsur, a local police chief.

"There were two foreigner vehicles that passed near my shop and a third private vehicle hit them, causing the explosion," said Ahmad Shah, whose shop is close to the blast site.

He said the attacker's vehicle and two of the contractors' vehicles caught fire after the explosion.

The foreigners from one of the vehicles that was lightly damaged fired their guns into the air to prevent civilians from approaching, Shah said.